In forecasting, a practical question often arises:Let’s presume t is the first period for which the model is solved i.e. all endogenous variables are unknown.Then, if we have information on endogenous for t or t+x, we can incorporate them in the solution with the model.exclude(actexist=t) statement.If however we have the following situation:x = y + zand if we observe x (which is an identity) but not y and/or z (which are endogenous behavioral), how can we guarantee the holding of the identity? This is a very practical question since in Macroeconomics, we often observe the aggregates before we observe the detailed components.Many thanksFerdy